Heat exchanger operating with solid mass particles as heat carrier



3, 1966 H. SONNENSCHEIN ETAL 3,283,810

HEAT EXCHANGER OPERATING WITH SOLID MASS PARTICLES AS HEAT CARRIER Filed NOV. 14, 1963 4 Sheets-Sheet 1 H. SONNENSCHEIN ETAL 3,283,810 HEAT EXCHANGER OPERATING WITH SOLID MASS PARTICLES AS HEAT CARRIER Nov. 8, 1966 4 Sheets-Sheet 2 Filed Nov. 14, 1963 FIG.3

FIGA

Nov. 8, 1966 H. SONNENSCHEIN ET AL HEAT EXCHANGER OPERATING WITH SOLID MA PARTICLES AS HEAT CARRIER 4 Sheets-Sheet 5 Filed NOV. 14, 1963 FIG 5a FIG. 5

FIG. 7

Nov. 8, 1966 H. SONNENSCHEIN ETAL 3,283,810 HEAT EXCHANGER OPERATING WITH SOLID MASS PARTICLES AS HEAT CARRIER Filed Nov. 14, 1963 4 Sheets-Sheet 4.

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I "3; 20 "a? r A V V 14a 14c 14b 14d 15a 15b United States Patent 3,283,810 HEAT EXCHANGER OPERATING WITH SOLID MASS PARTICLES AS HEAT CARRIER Hans Sonnenschein and Rudolf Friedrich, Mulheim an der Ruhr, Germany, assignors to Siemens-Schuckertwerke Aktiengesellschaft, Berlin, Germany, a corporation of Germany Filed Nov. 14, 1963, Ser. No. 323,781 11 Claims. (Ci. 165--96) Our invention relates to heat exchangers in which masses of heat-storing particles transfer heat from one gaseous medium to another.

In known equipment of this type a flow of solid particles travels in a circulatory path and is traversed by different heat-exchanging gases in separate chambers. In such heat exchangers, known as pebble heaters, the gaseous media pass through a rather thick layer of spherical solid particles which travel downwardly by gravity flow in opposition to the direction of the gas flow. Great difficulties barely surmountable in practice are encountered when attempting to employ equipment of such structure and operating principle in regenerators for large throughput and gas quantities and small bearable pressure drops.

A type of heat exchangers is also known in which the transfer of heat between two gaseous media is effected by means of a mass of heat-storing particles accommodated within a disc-shaped rotor. The layer of mass particles in the rotor is traversed by the gaseous media in respective opposite directions to effect a heat exchange on the counter-flow principle, despite the fact that the gaseous media have a flow direction transverse to the travel direction of the mass particles that rotate together with the rotor. In such heat exchangers, the gas currents are guided by a system of channels toward and away from the disc-shaped rotor body at the respective axial end sides thereof. Such devices afford the attainment of a relatively favorable heat exchange and a small pressure drop while requiring only relatively small space. Difficulties, however, are encountered in sealing the rotating heat-storing body relative to the required inlet and outlet channels for the different gaseous media which, distributed over the periphery of the heat-storing rotor, must be passed into and out of the heat-storing rotor,

It is an object of our invention to afford favorable heatexchanging conditions, together with a small pressure drop and the possibility of operating with large gas-flow quantities, without the necessity of providing a rotating heatstoring assembly, thus achieving the desired operating quantities with simpler and less troublesome means.

According to our invention, a heat-exchanger system is so constructed that the above-mentioned rotating heatstoring mass system is replaced by a continuous solid particle flow circulating in a stationary system of channels.

More specifically, and in accordance with further features of our invention, we provide a duct structure that is longitudinally traversed by a stream of heat-storing particles and forms two heat-exchange zones spaced from each other in the particle-flow direction. We further provide two pairs of gas conduits for passing two currents of gaseous media through the respective zones. The duct structure extends between the two conduits of each pair and has gas-permeable wall portions, such as louvered wall portions, through which the two conduits of each pair communicate with each other through one of the two heat-exchanging zones respectively. The duct structure further forms part of a circulatory distributor system which passes a particle flow of substantially uniform layer distribution through the duct structure and thus sequentially through the two heat-exchange zones. As a result, the flow layers of the particle mass assume respectively graduated temperatures due to the temperature difference 3,283,810 Patented Nov. 8, 1966 "ice of the respective gases passing through the two pairs of conduits, the gas-flow direction in the conduits being transverse to the particle-flow direction in the duct structure and in heat-exchanging counter-flow relation to each other.

According to further features of our invention, the two heat-exchange zones are separated from each other by one or more intermediate zones so constructed that the mass particles flowing by gravity through the intermediate zone retain the same layer-wise temperature distribution from one to the other heat-exchanger zone. The intermediate zone may have the same cross section as the heat-exchange zones, however, according to another feature of our invention, the cross section in the intermediate zone is made different from that of the heat-exchanger zones and preferably made smaller. A preferred construction is to provide the intermedite zone with wall members or partitions which cause the particle material to temporarily accumulate in the intermediate portion thereby preventing or reducing leakage of gas between the heat-exchange zones while simultaneously maintaining a given temperature distribution in the partitioned layers of the particle mass.

According to still another feature of our invention, we provide individual circulating channels with particle-mass conveying devices which connect the two heat-exchange zones outside of the above-mentioned duct structure in order to convey the mass particles in separate layers or strands from the lower heat-exchange zone to the other heat-exchange zone that is located on a higher level, while substantially maintaining the above-mentioned temperature distribution or graduation between the layers of the mass-particle flow that are being circulated.

Effective performance of the heat exchanger constructed according to the invention is provided by the intermediate zone and the subdivided external circulating system for the particle mass flow, which produce a temperature diiference between the two gases in the respective conduit pairs that causes the occurrence of a temperature distribution or graduation in a direction perpendicular to the travel direction of the mass particles operating as heat-transferring carriers, so that the heat exchange between the two gases in the respective conduit pairs corresponds, at least approximately, to counter-flow principle. This provides on the one hand more favorable heat-exchanging conditions and, on the other hand, a relatively large flow area for the heat-exchange zones to be traversed by the gaseous media, and also a small depth of the heat-exchange zones. The prerequisites are thereby met for securing a small pressure drop at very large gas-flow quantities.

In heat exchangers constructed according to the invention, the flow between the heat-exchanging zones is virtually homogeneous and maintains a given stratified temperature distribution. In the region of the heat-exchange zones, when the gas flow is particularly intensive, the flow 0f the mass particles may become disturbed due to the fact that the boundary layers may become differently influenced by gas forces. According to another feature of our invention, such disturbances in the particle flow can be prevented by vertically inclining the heat-exchanging zones, i.e. those portions of the duct structure that contain these zones, the inclination being at an angle at which the resultant of the gravity forces acting upon the mass particles and of the forces caused by the gas resistance encountered by the mass particles extends approximately in the longitudinal or axial direction of the heat-exchange zone.

The above-mentioned and other objects and features of our invention, said features being set forth with particularity in the claims annexed hereto, will be apparent from, and will be mentioned in, the following with reference to embodiments of heat exchangers according to the t l l l invention illustrated by way of example on the accompanying drawings in which:

FIG. 1 shows schematically and in vertical section a heat-exchanger system constructed in accordance with the invention.

FIG. 2 is a sectional view of the upper heat-exchanger zone and related ducts showing details of its construction.

FIG. 3 is a sectional view taken along the line IIIIII in FIG. 2, in the direction of the arrows.

FIG. 4 is a sectional view of the lower heat-exchanger zone showing construction details of the discharge duct system and the throughput regulating equipment.

FIG. 5 is a sectional view taken along the line VV in FIG. 4, in the direction of the arrows.

FIG. 5a is a sectional view taken along the line VaVa in FIG. 5, in the direction of the arrows.

FIG. 6' shows schematically a somewhat modified heatexchanger system in which the intermediate zone between the two heat-exchange zones is constricted in the flow direction of the gaseous media.

FIG. 7 shows schematically another modification of the system in which the cross section of the intermediate zone is constricted between the heat-exchange zones in a direction perpendicular to the gas-flow direction.

FIG. 8 shows schematically and in vertical section a further embodiment of the system in which the heatexchange zones are inclined so that the resulting force upon the mass particles extends in the longitudinal di rection of the heat-exchange zone.

Referring now to the drawings and particularly to FIG. 1, there is shown a vertically elongated duct structure of sheet metal which comprises an upper heat-exchange zone I and a lower heat-exchange zone II. Each of these zones is bordered by gas-permeable wall portions 1 in the duct structure and by gas-impermeable walls or partitions 2 at the respective front and rear ends thereof. A gas conduit 3 supplies a stream of cold gas laterally into the heat-exchange zone I, the flow direction being indicated by an arrow 4. The gas, after passing through the zone I and being heated therein, as described hereinafter, leaves the heat exchanger through a gas conduit 5 connected to the duct structure on the side opposite the gas supply duct 3.

FIGS. 2 and 3 show an enlargement of the structure of the heat-exchanger zone I and the inlet duct system 6 for the mass particles. The gas-permeable wall portions 1 are formed with a system of inclined ledges or louvers 1a which have a downward inclination from the outside toward the inside and are spaced from one another similar to a jalousie. The louvers 1a are connected to the transverse gas-impermeable walls 2. The gas-permeable walls 1 permit passage of the gas stream from and to the conduits 3 and 5 respectively. The inlet duct system 6 for the particulate mass by means of which uniform distribution of the mass particles in the heat-exchanger zone is effected, consists of a plurality of parallel branches 611-60. Each of the branches 6a-6c provided for the layer-like distribution consists essentially of a distributor 611 to Ge respectively, and a number of divider pipes. The sectional view in FIG. 3 taken along the line IIIIII of FIG. 2. clearly shows the arrangement of divider pipes 6a 6a for the channel branch 6a.

Depending upon the temperatures, sheet-steel or ceramic such as steatite, corundum or the like, is employed as material for the wall portions 1 and the louvers 1a, as well as for the conduits 3 and 5.

For heating the gas flow, the heat-exchange zone I is supplied from above with a mass of fine-granular particles A for example in the form of steel sand, quartz sand or ceramic particles which, under the effect of gravity, pass downwardly through the duct. The cold gas passing through the particle mass transversely to the travel direction of the particle mass is heated by the particles which are at a higher temperature. The mass particles after passing through the zone I travel through an intermediate zone III which is enclosed on all sides by a dense, impermeable wall portion 7 of the duct structure without change in the mass particle layers. The mass particles then pass downwardly into the heat-exchange zone II which, like the zone I, is bordered on two laterally opposite sides by gas-permeable wall portions 1, whereas impermeable wall portions 2 are provided at the axial sides of the zone. The structure of the zone II also corresponds to the structure of zone I as shown in FIGS. 2 and 3. A pair of conduits 8 and 9 serve to pass a hot gas from the left to the right through the heat-exchange zone II, as is indicated by the arrow 11, this hot gas being, for example, the waste gas from a turbine (not shown) which, when passing through the zone II heats the mass particles A in this zone to a higher temperature.

An outlet duct system 12 with a device 13 for regulating the throughput of the mass particles is provided for conducting the mass particles in layers out of zone II. The regulating apparatus 13 permits the feeding of the mass particles of the layers of varying temperatures through separate circulating ducts Ida-14c to the heatexchange zone II.

FIGS. 4 and 5 separately illustrate more clearly the construction of the outlet duct system 12 for the mass particles which follows the heat-exchange zone II and which comprises three parallel branching channels 12a, 12b, 12c and the throughput regulating apparatus 13. The parallel branches 12a12c of the outlet duct system 12 are arranged one behind the other in the travel direction of the gas stream flowing through the heat-exchanger zone II. As shown in FIG. 5 which is a sectional view along the line VV of FIG. 4, each of the channel branches 12a, 12b, 12c consists of a number of outlet pipes, pipes l2a l2a in the case of the channel branch 12a {see FIG. 5), the upper end of each channel branch discharging from inlet funnels arranged uniformly beneath the zone II, and the lower end of each channel branch being introduced into respective collecting boxes or reservoirs 12:1 1212 Consequently parts of the stream of mass-particle layers are fed from the collecting boxes 12%, 1217 120 through the multiple slide valve 13 by means of the servo-mechanism drive 13a to the circulating channels 14a to 140. The granular mass particles are then fed through the circulating channels I ia-14c, which are provided with suitable feed mechanisms 15a15c known in the art and hereinafter described, to the distributors 6a -6c of the channel branches 6a-6c respectively above the heat-exchanger zone I in distinct layer distribution once again.

To ensure uniform flow of the portions of mass particles through the channel branches 1211 12:1 12:2 which are shown in cross section in FIG. 5a, a view taken along the line VaVa in FIG. 5, the branch pipes 12:1 1211 12:1 are led into symmetrically subdivided chambers of the collecting boxes 12:1 12b 120 The branch pipes 12:1 -12:1 are located only at the upper part of the collecting boxes and an undivided flow space of unchanging cross section is connected thereto within the collecting boxes. Due to the homogeneous flow of the mass-particle columns through the flow space in the collecting boxes, the streams of portions of the particles are forced uniformly into the respective pipes lines 120 12a 12(1'3.

A screw conveyor 15a is shown in FIG. 1 as the feed apparatus 15a in the duct 14a, to which the mass particles flow by force of gravity through the duct branch 14a which is suitably arranged beneath the zone II and throughput regulating apparatus 13. The screw conveyor 15a, is rotatably driven by an electric motor 15:1 Corresponding screw conveyors are provided similarly in the ducts 14b and 140, but for simplicitys sake are not shown in the drawing. The mass portions that form the various heat layers of zone II are raised by the screw conveyors into the separate channels I la-14c and are led across the upper portions of the channels 14a14c that are arranged in inclined positions. Naturally, instead of screw conveyors, other feeding mechanisms can be provided, for example pneumatically operating feeding apparatuses, which raise the particles by means of gas pressure or the movement of a gas.

The intermediate zone III is longer than the heatexchange zones in the direction of the particulate mass flow. The intermediate zone thus separates the two heatexchange zones I and II which can be in certain cases under respectively different pressures, the intermediate zone being of sufiicient length for minimizing any leakage fiow of gas between the two conduit pairs. In the same manner, the flow resistance of the circulating channels or ducts 14a, 14b and 140 is provided with a length or cross section necessary for minimizing leakage flow of gas between the heat-exchange zones I and II.

For supplying the heat-exchanger system with mass particles, a filler or supply duct 18 is provided above the zone I, and for discharging the particles from the system, a discharge duct system 19 is connected to the channel means 14a to 14c beneath the zone II. If desired, a gate or slider means similar to the control device 12 can be provided for closing the supply duct 18 and discharge duct system 19 with respect to the heat-exchanger system proper. The positions of zones I and II can also be interchanged, i.e. zone I for cold gas can be located beneath zone II for hot gas.

The intermediate zone, the circulating channels for the heat-storin g particulate mass, and the heat-exchange zones that are provided afford production and maintenance in the heat-exchange zones I and II of a temperature stratification or gradation so that, in conjunction with a corresponding directed gas flow and particulate-mass flow, heat exchange substantially in accordance with counterfiow principles is produced in a manner similar to the heat-exchangin g performance of the aforementioned rotortype exchangers known in the art which operate with rough mass particles. The temperature distribution in the form of layers produced by the heat-storing mass particles which pass through the heat-exchange zones I and II and the intermediate zone III essentially without turbulence or vortex formation and thus in piston or laminar flow. form parallel to the walls 1, 2, 7 of these respective zones, and the separate circulation channels 14a, 14b, 140, which can be provided in any desired number, then return the massaparticle fiow tront zone II to zone I through the inlet hoppers or funnels 6a to 60 with the same temperature distribution. To secure proper guidance of the mass particles in the form of such temperature-graduated layers, the duct structure can be provided with guiding partitions such as those shown at 16, particularly in the intermediate zone III. The partitions consist preferably of sheet metal and are spaced from each other in a direction transverse to the-particleflow direction, each partition extending in a plane perpendicular to the direction of gas flow through the two pairs of gas conduits 3, 5 and 8, 9.

It is generally preferable to leave the heat-exchange zones I and 11 free of such intermediate partitions in order to minimize the resulting pressure drop. If desired, however, gas-permeable partitions or wall portions can also be provided in the heat-exchange zones. In this case, the permeable partitions, like the Wall portions 1, may consist of plates or profile structures that extend parallel to each other in the flow direction of the particle mass and are provided with louvered slots extending in the particle-flow direction and permitting the gas to pass through the partitions.

The provision of intermediate partitions members 16 is of particular advantage in heat exchangers that have a flow cross section for the particulate material which varies along the intermediate zone III. An embodiment of this kind is illustrated 11 FIG. 6 which shows essentially only the duct structure and gas conduits, the system being otherwise in accordance with that described 6 above with reference to FIG. 1. In the exchanger according to FIG. 6 the vertical duct structure has a constricted cross section along the major length of the intermediate zone III and is provided with partitioning inserts.

16 corresponding to those shown in FIG. 1 but merging with traditional portions 17 at the localities where the conduit portion of wider cross section merges gradually with the portion of smaller cross section. The reduction in cross section within the intermediate zone III of this embodiment is in a direction parallel to the :axial or gasfiow direction of the gas conduits 3, 5 and 8, 9. In contrast thereto, FIG. 7 shows schematically the intermediate-zone portion of another modification, seen at a right angle to the plane of illustration corresponding to FIG. 6. According to FIG. 7, the cross section of the intermediate zone III is constricted in a direction perpendicular to the fias-flow axis of the gas conduits and hence in a direction perpendlcular to the temperature Stratification of the particle flow in the duct structure. In an embodiment of the latter type subdividing partitioning members within the intermediate zone III can be dispensed with because suitable shaping of the flow cross section in the duct structure causes the particle flow to behave similar to a viscou flow mass which is not appreciably disturbed with respect to the path of the individual mass particles.

The heat exchanger exemplified in FIG. 8 differs from that of FIG. 1 essentially in that the two heat-exchange zones I and II are inclined at an angle a with respect to the vertical. Accordingly as shown diagram at 20 in zones I .and II, the resultant r or the gravity component g acting upon the individual mass particles and the force component w stemming from the gas resistance, extends parallel to the longitudinal (axial) direction of the respective heat-exchange zones. The embodiment according to FIG. 8 is further provided with arouate guide members 21 of sheet metal in the curved regions of the device, namely between the vertically extending portions of the duct structure and the inclined portions. In other respects the embodiment corresponds generally to the one described above with reference to FIG. 1, this being apparent from the use of the same reference characters for corresponding elements respectively.

To those skilled in the art it will .be obvious upon a study of this disclosure that heat exchangers according to our invention can be modified in various respects and hence can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of our invention and within the scope of the claims annexed hereto.

We claim:

1. A heat exchanger comprising a duct structure to be traversed by a flow of heat-storing particles, said structure forming two heat-exchange zones spaced from each other along the particle-flow direction, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gaspermeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, circulatory particle-mass distributing means communicating with said duct structure for circulating therethrough a particle flow of substantially uniform layer distribution in the particle-flow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pair of conduits, and means for maintaining substantially the same temperature distribution in the layers of particle flow from one to the other of said heat-exchange zones, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counterfiow relation to each other.

2. In a heat exchanger according to claim 1, said duct by the force structure having between said two heat-exchange zones an intermediate zone of the same duct cross section as said i heat-exchange zones.

3. In a heat exchanger according to claim 1, said duct structure having between said two heat-exchanger zones an intermediate zone, whose cross section is smaller than that of said heat-exchange zones, and guide partitions mounted in said intermediate zone and extending substantially parallel to the duct axis in planes perpendicular to the gas-flow direction.

4. A heat exchanger comprising a duct structure elongated in generally vertical direction to be downwardly traversed by a flow of heat-storing particles, said structure forming upper and lower heat-exchange zones vertically spaced from each other, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gas-permeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, particle-mass circulating means having a plurality of separate channels extending outside of said duct structure from below said lower zone to above said upper zone for circulating through said duct structure, a particle flow of substantially uniform layer distribution in the particleflow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits and means for maintaining substantially the same temperature distribution in the layers of particle flow from one to the other of said heat-exchange zones, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heatexchanging counter-flow relation to each other.

5. A heat exchanger comprising a duct structure elongated in generally vertical direction to be downwardly traversed by a flow of heat-storing particles, said structure forming upper and lower heat-exchange zones vertically spaced from each other, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gas-permeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, particle-mass circulating means having a plurality of separate channels extending outside of said duct structure from below said lower zone to above said upper zone for circulating through said duct structure, a particle flow of substantially uniform layer distribution in the particle-flow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counter-flow relation to each other, said duct structure having respective portions containing said zones, with the longitudinal center lines of said portions being inclined with respect to the vertical so the said center lines extend parallel to the line of action of the resultant of the force of gravity on a heat-storing particle and the frictional drag force resulting from the gas current flowing past a heat-storing particle.

6. A heat exchanger comprising a duct structure elongated in generally vertical direction to be downwardly traversed by a flow of heat-storing particles, said structure forming upper and lower heat-exchange zones vertically spaced from each other, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gas-permeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, particle-mass circulating means having a plurality of separate channels extending outside of said duct structure from below said lower zone to above said upper zone for cir- 8 culating through said duct structure, a particle flow of substantially uniform layer distribution in the particlefiow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counter-flow relation to each other, said duct structure having portions extending substantially vertically and portions inclined to the vertical, said zones being located in said inclined duct portions respectively, and partition members inserted between said vertical and said inclined portions for guiding the mass particles at the curved path localities, said members extending in the particle-flow direction in parallel and spaced relation to one another.

7. A heat exchanger comprising a duct structure to be traversed by a flow of heat-storing particles, said structure forming two heat-exchange zones spaced from each other along the particles-flow direction, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gaspermeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, circulatory particle-mass distributing means communicating with said duct structure for circulating therethrough a particle flow of substantially uniform layer distribution in the particle-flow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits, said circulatory distributing means comprising a plurality of substantially parallel conduits having a plurality of inlet and outlet channel systems connecting respectively with said heatexchanger zones for providing uniform passage of the layer particles to and from said heat-exchanger zones so that substantially the same temperature distribution is maintained in the layers of particle flow from one to the other to said heat-exchanger zones, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counter-flow relation to each other.

8. A heat exchanger comprising a duct structure to be traversed by a flow of heat-storing particles, said structure forming two-heat exchange zones spaced from each other along the particle-flow direction, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gas-permeable wall portions through which the two conduits of each pair communicate with each other through one of said zones, circulatory particle-mass distributing means communicating with said duct structure for circulating there through a particle How of substantially uniform layer distribution in the particle-flow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits, said circulatory distributing means comprising a plurality of substantially parallel conduits having a plurality of inlet and outlet channel systems connecting respectively with said heatexchanger zones for providing uniform passage of the layer particles to and from said heat-exchanger zones, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counter-flow relation to each other, said inlet channel systems including a plurality of distribution chambers and said outlet channel systems including a plurality of collection boxes.

9. In a heat exchanger according to claim 8, a portion of said collection boxes being formed with a plurality of subdivided symmetrical chambers and a portion of said collection boxes having an undivided flow space of uniform cross section, a plurality of channel members connecting the respective heat-exchange zone with the subdivided chambers of said collection boxes.

10. In a heat exchanger according to claim 1, regulating means provided in said circulatory distributing means for regulating the flow of particles through said distributing means.

11. A heat exchanger comprising a duct structure to be traversed by a flow of heat-storing particles, said structure forming two heat-exchange zones spaced from each other along the particle-flow direction, two pairs of gas conduits for passing two currents of gas through said respective zones, said duct structure extending between the two conduits of each pair and having respective gaspermeable .wall portions through which the two conduits of each pair communicate with each other through one of said zones, circulatory particle-mass distributing means communicating with said duct structure for circulating therethrough a particle flow of substantially uniform layer distribution in the particle-flow direction whereby the flow layers assume respectively graduated temperatures due to temperature difference of the respective gases passing through said two pairs of conduits, said conduit pairs having a gas-flow direction transverse to the particle-flow direction of said duct structure and in heat-exchanging counter-flow relation to each other, regulating means provided in said circulatory distributing means for regulating the flow of particles through said distributing means, said circulatory distributing means comprising 1 plurality of g substantially parallel conduits and said regulating means comprising a multiple slide valve inserted. in said conduits for regulating the substantially uniform distribution of particles through said conduits.

References Cited by the Examiner UNITED STATES PATENTS ROBERT A. OLEARY, Primary Examiner.

CHARLES SUKALO, Examiner.

N. R. WILSON, Assistant Examiner. 

1. A HEAT EXCHANGER COMPRISING A DUCT STRUCTURE TO BE TRAVERSED BY A FLOW OF HEAT-STORING PARTICLES, SAID STRUCTURE FORMING TWO HEAT-EXCHANGER ZONES SPACED FROM EACH OTHER ALONG THE PARTICLE-FLOW DIRECTION, TWO PAIRS OF GAS CONDUITS FOR PASSING TWO CURRENTS OF GAS THROUGH SAID RESPECTIVE ZONES, SAID DUCT STRUCTURE EXTENDING BETWEEN THE TWO CONDUITS OF EACH PAIR AND HAVING RESPECTIVE GASPERMEABLE WALL PORTIONS THROUGH WHICH THE TWO CONDUITS OF EACH PAIR COMMUNICATE WITH EACH OTHER THROUGH ONE OF SAID ZONES, CIRCULATORY PARTICLE-MASS DISTRIBUTING MEANS COMMUNICATING WITH SAID DUCT STRUCTURE FOR CIRCULATING THERETHROUGH A PARTICLE FLOW OF SUBSTANTIALLY UNIFORM LAYER DISTRIBUTION IN THE PARTICLE-FLOW DIRECTION WHEREBY THE FLOW LAYERS ASSUME RESPECTIVELY GRADUATED TEMPERATURES DUE TO TEMPERATURE DIFFERENCE OF THE RESPECTIVE GASES PASSING THROUGH SAID TWO PAIR OF CONDUITS, AND MEANS FOR MAINTAINING SUBSTANTIALLY THE SAME TEMPERATURE DISTRIBUTION IN THE LAYERS OF PARTICLE FLOW FROM ONE TO THE OTHER OF SAID HEAT-EXCHANGE ZONES, SAID CONDUIT PAIRS HAVING A GAS-FLOW DIRECTION TRANSVERSE TO THE PARTICLE-FLOW DIRECTION OF SAID DUCT STRUCTURE AND IN HEAT-EXCHANGING COUNTERFLOW RELATION TO EACH OTHER. 